Photonic crystal structure and method of manufacturing the same

Abstract

A photonic crystal structure is provided the optical characteristics of which vary periodically in at least one direction, wherein the base material of the photonic crystal structure is formed of a dielectric material, a region containing at least one of molecules, atoms and ions different from the constituent element of the base material is provided in the base material, and the region is arranged in the base material so that the density of one of the molecules, atoms and ions varies periodically in the one direction.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a photonic crystal structure and a method of manufacturing the photonic crystal structure.[0003]2. Related Background Art[0004]A photonic crystal is a structure in which the refractive indexes of constituent substances are distributed periodically. The photonic crystal is an artificial material capable of realizing novel functions simply by means of structural design. The most noteworthy feature of the photonic crystal is that there is formed therein a so-called photonic band gap, a region through which a specific electromagnetic wave cannot propagate because of the refractive index difference and structural periodicity of constituent materials. When a defect is introduced into the refractive index distribution of the photonic crystal, an energy level (defect level) due to this defect is formed in the photonic band gap. Consequently, the photonic crystal can freely control electromagneti...

AI Technical Summary

Benefits of technology

[0029]According to the present invention, it is possible to provide a photonic crystal structure capable of improving device characteristics. It is also possible to realize a method of manufacturing a photonic crystal structure whereby a complex three-dimensional structure, a nanophotonic crystal in particular, can be manufactured with precision and simplicity and at low costs.

Problems solved by technology

Whereas ideal device characteristics are expected from the three-dimensional photonic crystal having such a microscopic three-dimensional structure as described above, the photonic crystal is generally complex in structure and requires many cumbersome steps for manufacturing.

As a result, requirements for interlayer alignment accuracy and structural processing accuracy become increasingly stringent.

In addition, the interlayer alignment error is desirably less than approximately 25% of the rod period.

This means that the processing error of each rod is less than approximately ±25 nm and each interlayer alignment error is less than approximately ±60 nm.

However, such a conventional laminating method as described in patent document 3 poses the problem, when manufacturing the three-dimensional photonic crystal, that a manufacture method is complex, the number of steps increases in proportion to the number of layers of the photonic crystal and, therefore, the degree of technical difficulty increases, though existing semiconductor technologies can be applied.

Consequently, with such a method as described above, it is extremely difficult to improve productivity.

Another problem is that the accumulation of alignment errors is unavoidable since alignment is necessary at each time of lamination.

In addition, not only the discontinuity of material (i.e., refractive index) occurs in each interlaminar interface but also dust adhesion or contamination unavoidable in a manufacturing process occurs, thereby causing unwanted electromagnetic wave scattering.

Furthermore, a structural deformation also occurs since stress inside a structure increases with an increase in the number of layers.

These structural disorders adversely affect the characteristics of the photonic crystal device.

From these considerations, it is difficult to precisely manufacture the three-dimensional photonic crystal with the above-described conventional laminating method.

However, no solutions have been proposed yet to the problem of enabling the manufacture of a three-dimensional photonic crystal having such a complex structure as a woodpile structure using these techniques.

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